Nortel Networks 411-2021-111 manual Introduction, Northern Telecoms DualMode Metrocell

1-1

Introduction

Northern Telecom's DualMode Metrocell

As cellular systems evolve to the digital format, service providers and mobile subscribers are confronted by a mixture of analog and digital technologies. Northern Telecom (Nortel)’s dual mode cellular product allows a smooth transition from analog to digital technology. It uses Time Division Multiple Access (TDMA) technology for digital systems and Advanced Mobile Phone Service (AMPS) technology for analog systems. This evolutionary strategy enables service providers to gradually upgrade their cellular systems to digital while providing support of existing analog equipment.

The Nortel cellularsystem supporting dual mode service includesthe following components:

•the DMS-MTX switch containing the Intelligent Cellular Peripheral (ICP) unit at the mobile switching office

•dual mode cell sites with the configurable DualMode Radio Units (DRU) on a Radio Frequency (RF) Frame and the Integrated Cellular Remote Module (ICRM), on a Common Equipment (CE) Frame at the cell site

•external and internal interface links.

The Nortel DualMode Metrocell serves as the intelligent interface between a Digital Multiplex Switch - Mobile Telephone Exchange (DMS-MTX) and its registered cellular mobiles. It is a dual mode cell that works in both the analog (AMPS) mode and the digital (TDMA) mode.

The Metrocell is designed for high density, small radius cells in areas where large traffic capacity is required. It can exist independently or it can be added to existing cells for increased coverage. The Metrocell provides a reduced power output for urban applications. The typical power output of the Power Amplifier (PA) is 22 watts (43.5 dBm).

Figure 1-1 shows the architecture of a DualMode Metrocell system and

Figure 1-2 is a block diagram of the product of the system.

DMS-MTX DualMode Metrocell Cell Site Description